Methods and devices for correcting spinal deformities

ABSTRACT

Method and devices are provided for correction of spinal deformities. The methods and devices are particularly useful for correcting an abnormal curvature of the spine. In one exemplary embodiment, the methods and devices provide a spinal implant that can include a wedged-shape configuration. The wedged implant can be interposed between adjacent vertebrae that form part of an abnormal spinal curvature, thereby realigning the vertebrae and restoring the normal curvature to the spine.

FIELD OF THE INVENTION

The present invention relates to methods and devices for correctingspinal deformities.

BACKGROUND OF THE INVENTION

Spinal deformities, which include rotation, angulation, and/or curvatureof the spine, can result from various disorders, including, for example,scoliosis (abnormal curvature in the coronal plane of the spine),kyphosis (backward curvature of the spine), and spondylolisthesis(forward displacement of a lumbar vertebra). Other causes of anabnormally shaped spine include trauma and spinal degeneration withadvancing age. Early techniques for correcting such deformities utilizedexternal devices that applied force to the spine in an attempt toreposition the vertebrae. These devices, however, resulted in severerestriction and in some cases immobility of the patient. Furthermore,current external braces have limited ability to correct the deformedspine and typically only prevent progression of the deformity.

More recent techniques for correcting spinal deformities utilize fusingof adjacent vertebrae through the disc space (the space previouslyoccupied by the spinal disc interposed between the adjacent vertebrae),known as spinal fusion. Typically, a fusion cage and/or bone graft isplaced into the disc space to position the vertebrae apart so as tocreate more space for the nerves, to restore the angular relationshipbetween the adjacent vertebrae to be fused, and to provide for materialthat can participate in and promote the fusion process. While currentspinal fusion techniques are effective, they typically require multiplelevels of vertebrae to be fused.

Accordingly, there remains a need for improved methods and devices forcorrecting an abnormal spinal curvature.

SUMMARY OF THE INVENTION

The present invention generally provides methods and devices forcorrecting spinal deformities. In one embodiment, a method forcorrecting a spinal deformity is provided and includes inserting aspinal implant into a disc space formed between two adjacent vertebraelocated along a curvature resulting from a deformity in a spinal column.The disc space can include a first lateral side located adjacent to aconcave side of the curvature in the spinal column and a second lateralside located adjacent to a convex side of the curvature in the spinalcolumn, and the spinal implant can have a wedge-shaped configurationwith a first side having a height that is greater than a height of asecond opposite side. The first side of the spinal implant can bepositioned adjacent the first lateral side of the disc space such that aheight of the first lateral side of the disc space is greater than aheight of the second lateral side of the disc space. The second oppositeside of the spinal implant can optionally be positioned adjacent thesecond lateral side of the disc space. In one exemplary embodiment, thespinal implant can have a footprint that substantially matches afootprint of the endplates of the adjacent vertebrae.

In another embodiment, the method can include inserting a second spinalimplant into the disc space. The second spinal implant can have awedged-shaped configuration with a first side having a height greaterthan a height of a second opposite. The height of the first side of thesecond spinal implant can be less than the height of the first side ofthe first spinal implant. The second side of the second spinal implantcan be positioned adjacent the second lateral side of the disc space.

In another embodiment, the spinal implant can have opposed posterior andanterior sides extending between the first and second sides, and theposterior side of the spinal implant can have a height greater than aheight of the anterior side such that a height of a posterior side ofthe disc space is greater than a height of an anterior side of the discspace. In another embodiment, the spinal implant can have opposedposterior and anterior sides extending between the first and secondsides, and the anterior side of the spinal implant can have a heightgreater than a height of the posterior side such that a height of ananterior side of the disc space is greater than a height of a posteriorside of the disc space.

The present invention also provides various techniques for inserting andpositioning a spinal implant between adjacent vertebrae. In oneembodiment, the spinal implant can be inserted through an incisionformed in an anterior side of a patient's body, and the implant can bepositioned such that it fills a substantial portion of the disc space.In another embodiment, the spinal implant can be inserted through anincision formed in a posterior side of a patient's body, and it can beguided into a position adjacent the concave side of the curvature of thespinal column. In yet another embodiment, the method can includeinserting a second spinal implant through the incision formed in theposterior side of the patient's body, and guiding the second spinalimplant into a position adjacent the convex side of the curvature of thespinal column.

In other aspects, the various methods can also include removing at leasta portion of an intervertebral disc located between the adjacentvertebrae prior to inserting the spinal implant, and/or mating at leastone connecting element extending longitudinally along the spinal columnto the adjacent vertebrae.

In yet another embodiment, a method for correcting a spinal deformity isprovided and includes inserting a wedged implant between two adjacentvertebrae located at an apex of a curvature resulting from a deformityin a spinal column. The wedged implant can be oriented such that aheight between the adjacent vertebrae is increased along a concave sideof the curvature to interrupt the curvature of the spinal deformity andthereby correct the spinal deformity. The implant can be insertedbetween the vertebrae using various approaches including a posteriorapproach or an anterior approach.

In yet another embodiment, the implant can be positioned into a discspace between adjacent vertebrae in a deflated configuration, and it canbe inflated such that the implant has a wedge-shaped configuration witha first side having a height that is greater than a height of a secondopposite side to thereby increase a height between the adjacentvertebrae along a concave side of the curvature. This allows the implantto be introduced into the disc space from a convex side of a curvaturein the spinal column. In an exemplary embodiment, the implant isinflated with a material that hardens such that the inflated implant isrigid.

In other aspects, the implant can be positioned in the disc space in afirst orientation in which a first side of the implant has a height thatis less than a height of a second opposite side of the implant. Theimplant can then be adjusted into a final orientation in which the firstside has a height that is greater than a height of the second oppositeside to thereby increase a height between the adjacent vertebrae along aconcave side of a curvature.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a coronal view of a spinal column showing abnormal curvaturesof the spine;

FIG. 1B is a sagittal view of the spinal column showing abnormalcurvatures of the spine;

FIG. 1C is a schematic showing a curvature of the spine with a wedgedimplant positioned at an apex of the curvature to interrupt and correctthe curvature;

FIG. 2A is a perspective view of one embodiment of spinal implant havinga medial-lateral wedge for correcting a curvature in the coronal planeof a spine;

FIG. 2B is an anterior coronal view of adjacent vertebrae of a spinalcolumn having an abnormal curvature, showing the wedge-shaped spinalimplant of FIG. 2A about to be inserted between the adjacent vertebrae;

FIG. 2C is an anterior coronal view of the adjacent vertebrae andimplant of FIG. 2B, showing the implant positioned between adjacentvertebrae;

FIG. 3 is a perspective view of another embodiment of a spinal implanthaving a medial-lateral wedge and an anterior-posterior wedge forcorrecting a curvature in the coronal and sagittal planes of a spinalcolumn;

FIG. 4A is a perspective view of yet another embodiment of a spinalimplant having a medial-lateral wedge and an anterior-posterior wedgefor correcting a curvature in the coronal and sagittal planes of aspinal column;

FIG. 4B is a posterior coronal view of two adjacent vertebrae of aspinal column, showing an abnormal coronal curvature;

FIG. 4C is a side sagittal view of the adjacent vertebrae of FIG. 4B,showing an abnormal sagittal curvature;

FIG. 4D is a posterior coronal view of the adjacent vertebrae of FIG.4B, showing the spinal implant of FIG. 4A inserted between the adjacentvertebrae for correcting the coronal curvature;

FIG. 4E is a side sagittal view of the adjacent vertebrae and spinalimplant of FIG. 4D, showing the spinal implant positioned to correct thesagittal curvature;

FIG. 4F is a superior view of one of the vertebrae of FIGS. 4D and 4E,showing the implant positioned on a lateral side of the disc space;

FIG. 5A is a perspective view of yet another embodiment of a spinalimplant having a medial-lateral wedge and an anterior-posterior wedgefor correcting a curvature in the coronal and sagittal planes of aspinal column;

FIG. 5B is a posterior coronal view of two adjacent vertebrae of aspinal column, showing an abnormal coronal curvature;

FIG. 5C is a side sagittal view of the adjacent vertebrae of FIG. 5B,showing an abnormal sagittal curvature;

FIG. 5D is a posterior coronal view of the adjacent vertebrae of FIG.5B, showing two implants having the configuration shown in FIG. 5Apositioned between the adjacent vertebrae to correct the coronalcurvature;

FIG. 5E is a side sagittal view of the adjacent vertebrae and spinalimplants of FIG. 5D, showing the implants positioned to correct thesagittal curvature;

FIG. 6A is a side view of another embodiment of a spinal implantpositioned between adjacent vertebrae, shown in a deflatedconfiguration;

FIG. 6B is a side view of the spinal implant of FIG. 6A, shown in aninflated configuration;

FIG. 7A is a side view of one embodiment of an adjustable spinalimplant, shown in a neutral configuration;

FIG. 7B is a side view of the adjustable spinal implant of FIG. 7A,shown in an initial configuration;

FIG. 7C is a side view of the adjustable spinal implant of FIG. 7A,shown in a final configuration;

FIG. 7D is a side view of the adjustable spinal implant of FIG. 7Apositioned between adjacent vertebrae, shown in an initialconfiguration;

FIG. 7E is a side view of the adjustable spinal implant of FIG. 7A,shown in a final configuration; and

FIG. 8 is posterior view of a portion of a spinal column, showing animplant positioned between two adjacent vertebrae and showing first andsecond spinal fixation elements coupled to the adjacent vertebrae.

DETAILED DESCRIPTION OF THE INVENTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those of ordinary skill in the art will understand that thedevices and methods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

The present invention generally provides methods and devices forcorrecting spinal deformities, and in particular for correcting anabnormal curvature in the spine. In general, various wedge-shapedimplants are provided that can be used to correct a deformity. In anexemplary embodiment, one or more implants can be positioned betweenadjacent vertebrae located at a substantial apex of a curvature in thecoronal plane of the spine to increase a height between the vertebrae ona lateral side of the disc space adjacent to the concave side of thecurvature. FIG. 1A illustrates various curvatures located in the coronalplane of a spinal column. Reference A indicates the substantial apex ofeach curvature, reference B indicates the convex side of each curvature,and reference C indicates the concave side of each curvature. Thus, inan exemplary embodiment, at least a portion of at least one implant canbe positioned between adjacent vertebrae located at a substantial apex Aof a curvature in the coronal plane. The implant(s) can be positionedsuch that a height of the implant(s) increases in a medial-lateraldirection relative to the disc space, and the maximum height of theimplant is positioned adjacent to the concave side C of the curvature.This will allow the implant(s) to essentially break the curvature,thereby forming two smaller curvatures of the spine, as shown in FIG.1C. In addition to correcting a curvature in the coronal plane, theimplant(s) can also optionally correct a curvature in the sagittal planeof the spine. FIG. 1B illustrates various curvatures located in thesagittal plane, and again reference A indicates the apex of eachcurvature, reference B indicates the convex side of each curvature, andreference C indicates the concave side of each curvature. One or morespinal implants positioned between adjacent vertebrae located at theapex A of a curvature can have a height that increases in aposterior-anterior direction, and the maximum height of the implant canbe positioned adjacent to the concave side C of the curvature to correctthe curvature in the sagittal pane.

A person skilled in the art will appreciate that the various spinalimplants disclosed herein are merely exemplary embodiments, and that theimplants can have a variety of other configurations and features toachieve correction of a curvature in the coronal and/or sagittal planesof the spine. Moreover, the methods and devices can be used in variousregions of the spine, including the cervical, thoracic and lumbarregions of the spine.

FIG. 2A illustrates one exemplary embodiment of an intervertebral spinalimplant 10. In this embodiment, the implant 10 is wedged in amedial-lateral direction to correct a deformity in the coronal plane ofthe spine. As shown, the spinal implant 10 generally includes a bodyhaving a disc-shaped configuration such that the implant 10 isconfigured to match the footprint of an endplate of a vertebra. Theimplant 10 can thus occupy all or at least a substantial portion of thedisc space between adjacent vertebrae. As further shown, the implant 10includes opposed first and second lateral sides 12 a, 12 b that areconfigured to be positioned adjacent to opposed lateral sides of a discspace between adjacent vertebrae. The implant 10 also includes opposedanterior and posterior sides 14 a, 14 b extending between the opposedfirst and second lateral sides 12 a, 12 b and configured to bepositioned adjacent to posterior and anterior sides of a disc space. Thesides 12 a, 12 b, 14 a, 14 b are connected by opposed superior andinferior surfaces 16 a, 16 b which are configured to be positionedadjacent to the endplates of adjacent superior and inferior vertebrae.As indicated above, the illustrated implant 10 can be wedged in amedial-lateral direction to correct a deformity in the coronal plane. Asshown in FIG. 2A, the first lateral side 12 a has a height h₁ that isgreater than a height h₂ of the second lateral side 12 b of the implant10. The difference in height can vary depending on the desired degree ofcorrection needed, but in an exemplary embodiment the height of theimplant increases at an angle α in the range of about 5° to 30°.

In use, as shown in FIGS. 2B-2C, the wedged-shaped spinal implant 10 canbe positioned between adjacent vertebrae located at a substantial apex Aof a curvature in the coronal plane of the spine (shown in FIG. 1A) tointerrupt the curvature and thereby correct the deformity. While varioustechniques known in the art can be used to introduce the implant 10 intothe disc space, in one exemplary embodiment the implant 10 can beintroduced using an anterior approach, also known as an anterior lumbarinterbody fusion (ALIF) technique. This approach is particularly usefulwith implants having a shape and size that matches the footprint of anendplate of a vertebra, as the anterior approach allows for additionalspace to introduce the implant. In general, an incision is formed in ananterior side of a patient's body, and a pathway is formed to theadjacent vertebrae between which the implant is to be inserted. Acannula or other device can be used to form a pathway from the skinincision to the disc space. In an exemplary embodiment, the nucleuspulposus of the natural disc can be removed from the disc space, leavinga portion of the annulus fibrosus of the disc in place.

Once the disc space is prepared, the implant 10 can be passed throughthe pathway and oriented between two adjacent vertebrae such that theabnormal curvature is interrupted leading to correction of the spinaldeformity. FIG. 2B illustrates a curvature in a coronal plane of severaladjacent vertebrae of a spine, showing a convex side B of the curvatureand a concave side A of the curvature. As shown in FIGS. 2B and 2C, theimplant 10 is preferably introduced into the disc space located adjacentto the apex A of the curvature. In order to correct the curvature, theimplant 10 is oriented such that the first lateral side 12 a, i.e., theside having the maximum height, is located on the lateral side of thedisc space adjacent to the concave side C of the curvature. The opposedsecond lateral side 12 b, i.e., the side having the minimum height, islocated on the opposed lateral side of the disc space adjacent to theconvex side B of the curvature. As a result, the implant 10 interruptsthe curvature in the coronal plane, thereby correcting the deformity, asshown in FIG. 2C. A person skilled in the art will appreciate that theheight of the implant 10 can also be sufficient to restore normal heightto the disc space between the adjacent vertebrae.

While the implant of FIG. 2A is wedged in a medial-lateral direction tocorrect a curvature in the coronal plane, the implant can alsooptionally be wedged in the posterior-anterior direction to correct acurvature in the sagittal plane. FIG. 3 illustrates one exemplaryembodiment of a spinal implant that is wedged in both the medial-lateraland posterior-anterior directions. As shown, the spinal implant 30 has ashape and size that is similar to the implant 10 of FIG. 2. Inparticular, the implant 30 includes first and second opposed lateralsides 32 a, 32 b, opposed anterior and posterior sides 34 a, 34 b, andopposed superior and inferior surfaces 36 a, 36 b. As with the implant10 of FIG. 2, the first lateral side 32 a of the implant 30 shown inFIG. 3 has a height h₃ that is greater than a height h₄ of the secondlateral side 32 b of the implant 30. In this embodiment, the posteriorside 34 b of the implant 30 also has a height h₅ that is greater than aheight h₆ of the anterior side 34 a of the implant 30. The implant 30 isthus wedged in both the medial-lateral direction and theposterior-anterior direction. A person skilled in the art willappreciate that the height h₃, h₄ on the lateral sides 32 a, 32 b willnot be constant, but rather will necessarily increase from the anteriorend of each lateral side 32 a, 32 b to the posterior end of each lateralside 32 a, 32 b. The height h₅, h₆ on the anterior and posterior sides34 a, 34 b will likewise increase from one lateral end of each side 34a, 34 b to the other lateral end of each side 34 a, 34 b. Thus, whileeach side 32 a, 32 b, 34 a, 34 b of the implant 30 is described ashaving a height h₃, h₄, h₅, h₆, the height is intended to refer to theheight along the entire length a side of the implant.

In use, the implant 30 can be inserted between two adjacent vertebrae ina spinal column to correct curvatures in both the coronal and sagittalplanes. As previously explained, the implant is preferably positionedbetween the vertebrae located at the apex of the curvature beingcorrected. Various techniques can be used for introducing the implant 30into the disc space, but in an exemplary embodiment the implant 30 isintroduced using an ALIF approach, as previously explained above. Oncethe implant 30 is positioned within the disc space, the implant 30 canbe oriented such that the maximum height in the medial-lateral directionis positioned adjacent to the concave side of a curvature in the coronalplane, and the maximum height in the posterior-anterior direction ispositioned adjacent to the concave side of the curvature in the sagittalplane. In particular, the first lateral side 32 a (i.e., themedial-lateral side having the maximum height) can be positioned on thelateral side of the disc space that is adjacent to the concave side of acurvature in the coronal plane, and the second lateral side 32 b can bepositioned on the opposed lateral side of the disc space that isadjacent to the convex side of the curvature in the coronal plane. Wherethe sagittal plane is curved such that the anterior side of the discspace is located adjacent to the convex side of the curvature and theposterior side of the disc space is located adjacent to the concave sideof the curvature, the posterior side 34 b (i.e., the posterior-anteriorside having the maximum height) can be positioned adjacent to theposterior side of the disc space and thus adjacent to the concave sideof the curvature, and the anterior side 34 a can be positioned adjacentto the anterior side of the disc space and thus adjacent to the convexside of the curvature. Conversely, where the sagittal plane is curvedsuch that the anterior side of the disc space is located adjacent to theconcave side of the curvature and the posterior side of the disc spaceis located adjacent to the convex side of the curvature, the posteriorside 34 b of the implant 30 can be positioned adjacent to the anteriorside of the disc space and thus adjacent to the concave side of thecurvature, and the posterior side 34 a can be positioned adjacent to theanterior side of the disc space and thus adjacent to the convex side ofthe curvature. A person skilled in the art will appreciate that theterms posterior-anterior are used for reference purposes only.

FIG. 4A illustrates another exemplary embodiment of a spinal implantthat is wedged in both the medial-lateral and posterior-anteriordirections. As shown, implant 40 has a bean-shaped configuration. Inparticular, the implant 40 includes opposed anterior and posterior sides42 a, 42 b, first and second opposed lateral sides 44 a, 44 b, andopposed superior and inferior surfaces 46 a, 46 b. In this embodiment,the anterior side 42 a of the implant 40 has a height h₇ that is greaterthan a height h₈ of the posterior side 42 b of the implant 40. Asfurther shown in FIG. 4A, the second lateral side 44 b of the implant 40has a height h₉ that is greater than a height h₁₀ of the opposing firstlateral side 44 a of the implant 40. Therefore, the implant 40 is wedgedin both the medial-lateral and posterior-anterior directions. A personskilled in the art will appreciate that the height h₇, h₈ on theanterior and posterior sides 42 a, 42 b will not be constant, but ratherwill necessarily increase from one lateral end of each side of 42 a, 42b to the other lateral end of each side of 42 a, 42 b, and that theheight h₉, h₁₀ on the lateral sides 44 a, 44 b will likewise increasefrom the anterior end of each side 44 a, 44 b to the posterior end ofeach side 44 a, 44 b.

In use, as shown in FIGS. 4B-4F, the spinal implant 40 can be insertedbetween two adjacent vertebrae located at a substantial apex A of acurvature in both the coronal (FIG. 4B) and sagittal (FIG. 4C) planes ofthe spine. Various techniques can be used for introducing the implantinto the disc space, but in an exemplary embodiment the implant 40 canbe introduced using a transforaminal lumbar interbody fusion (TLIF)approach. In general, in a TLIF approach the spinal column is accessedfrom the posterior side of a patient. An incision is formed in theposterior side of a patient's body, and a pathway is formed to theadjacent vertebrae between which the implant is inserted. A cannula orother device can be used to form a pathway from the skin incision to thedisc space. The intervertebral disc or portions thereof can then beremoved from the disc space.

Following preparation of the disc space, the implant 40 can be insertedthrough the pathway across the midline or in a medial-lateral direction.The bean-shaped configuration of the implant 40 is particularly usefulfor guiding the implant 40 across the midline and along a curvedpathway. Once inserted, the implant 40 can be oriented between twoadjacent vertebrae located at the apex A of the curvature such that theabnormal curvature is interrupted, thereby correcting the spinaldeformity. As illustrated in FIGS. 4B and 4D, when the abnormalcurvature is in the coronal plane of the spine, the implant 40 can beoriented such that second lateral side 44 b (i.e., the medial-lateralside having the greater height) is positioned on the lateral side of thedisc space that is adjacent to the concave side C of the curvature, andthe first lateral side 44 a is facing in the direction of the convexside B of the curvature. In this embodiment, the implant 40 isconfigured to remain within one lateral side of the disc space. This isillustrated in FIG. 4F, which shows a top view of the spinal implant 40positioned in the disc space of a vertebral body such that the implant40 occupies only one lateral side of the disc space. While not shown, asecond implant can optionally be implanted in the opposed lateral sideof the disc space. As further shown in FIGS. 4C and 4E, the implant 40can also correct an abnormal curvature in the sagittal plane. FIG. 4Cillustrates the anterior side of the disc space located adjacent theconcave side C of the curvature and the posterior side of the disc spacelocated adjacent the convex side B of the curvature. As shown in FIG.4E, the abnormal curvature can be corrected by orientating the implant40 such that anterior side 42 a (i.e. the anterior-posterior side havingthe greater height) is positioned adjacent to the anterior side of thedisc space and thus adjacent to the concave side C of the curvature, andthe posterior side 42 b is positioned adjacent to the posterior side ofthe disc space and thus adjacent to the convex side B of the curvature.As a result, the implant will correct the deformity in the coronal andsagittal plane.

FIG. 5A illustrates yet another exemplary embodiment of a spinal implantthat is wedged in both the medial-lateral and anterior-posteriordirections. In this embodiment, the implant 50 is similar to implant 40but has a rectangular-shaped configuration. In particular, the implant50 includes first and second opposed lateral sides 52 a, 52 b, opposedanterior and posterior sides 54 a, 54 b, and opposed superior andinferior surfaces 56 a, 56 b. As with the implant 40 of FIG. 4A, thesecond lateral side 52 b of the implant 50 has a height h_(b) that isgreater than a height h_(a) of the first lateral side 52 a of theimplant 50. However, in this embodiment, the posterior side 54 b ofimplant 50 has a height h_(d) that is greater than a height h_(c) of theanterior side 54 a of the implant 50.

FIGS. 5B-5E illustrate one exemplary method for correcting a deformityin both the coronal and sagittal planes using the implant 50 of FIG. 5A.In this embodiment, a first implant 50 is positioned within a firstlateral side of a disc space and a second implant 50′ is positionedwithin a second opposed lateral side of a disc space. The implants 50,50′ are preferably positioned between the vertebrae located at the apexof the curvature being corrected. Although various techniques can beused for introducing the implants 50, 50′ into the intervertebral discspace, in an exemplary embodiment the implants 50, 50′ are introducedusing a posterior lumbar interbody fusion (PLIF) approach. The PLIFapproach is similar to the TLIF approach discussed with respect toimplant 40, except that incisions are formed on each lateral side of thepatient's back to allow each implant 50, 50′ to be introduced alongseparate pathways. When the implants 50, 50′ are positioned within thedisc space, the implants 50, 50′ can be oriented such that the greaterheight in the medial-lateral direction is positioned adjacent theconcave side C of a curvature in the coronal plane (FIG. 5B), and thegreater height in the posterior-anterior direction is positionedadjacent to the concave side C of the curvature in the sagittal plane(FIG. 5C). In particular, as illustrated in FIG. 5D, the first implant50 can be positioned between two vertebrae located at a substantial apexA of a curvature in a coronal plane, and it can be positioned on onelateral side of the disc space. As shown, the implant 50 can be orientedsuch that the first lateral side 52 a of the implant 50 faces themidportion of the disc space and the second lateral side 52 b (i.e., themedial-lateral side having a maximum height) is positioned adjacent tothe concave side C of the curvature. The second implant 50′ is can bepositioned between the two vertebrae in the opposed lateral side of thedisc space opposite the first implant 50. The second implant 50′ islikewise oriented such that the first lateral side 52 a′ is positionedadjacent to the convex side B of the curvature, and the second lateralside 52 b′ (i.e., the medial-lateral side having a maximum height) ofthe implant 50′ faces the mid-portion of the disc space. In order toproperly correct the curvature, second implant 50′ preferably has anoverall height (i.e., a height on each side) that is less than anoverall height of the first implant 50, such that the two implants 50,50′ have a combined wedge-configuration.

As previously indicated, the implants 50, 50′ can also correct acurvature in the sagittal plane. FIG. 5C illustrates the sagittal planecurved such that the anterior side of the disc space is located adjacentthe convex side B of the curvature and the posterior side of the discspace is located adjacent the concave side C of the curvature. As shownin the FIG. 5E, the first implant 50 can be positioned between thevertebrae such that the anterior side 54 a of the implant 50 ispositioned adjacent to the anterior side of the disc space and thusadjacent to the convex side B of the curvature, and the posterior side54 b (i.e., the anterior-posterior side having a maximum height) ispositioned adjacent to the posterior side of the disc space and thusadjacent to the concave side C of the curvature. While not shown, thesecond implant 50′ can likewise be oriented to position theposterior-anterior side having the maximum height adjacent to theposterior side of the disc space, and thus adjacent to the concave sideC of the curvature.

FIGS. 6A-6B illustrate yet another exemplary embodiment of a spinalimplant. In this embodiment, the spinal implant 60 is inflated and has apre-formed configuration, such as, for example, a balloon. As shown, theimplant 60 can have a deflated configuration (FIG. 6A), and it can beinflated such that the implant 60 has a wedged-shaped configuration(FIG. 6B). The implant 60 can also include first and second opposedlateral sides 62 a, 62 b, and opposed superior and inferior surfaces 64a, 64 b. As further shown in FIG. 6B, when inflated, the first lateralside 62 a of the implant 60 can have a height h_(i) that is greater thana height h_(ii) of the opposed second lateral side 62 b of the implant60. The implant 60 can be inflated using a variety of known inflationdevices, such as, for example, a syringe 100 as shown in FIGS. 6A-6B.The implant 60 can also be inflated using a variety of materials, butpreferably, to ensure that the implant 60 retains the wedge-shapedconfiguration once inflated, the implant 60 is filled with a materialthat hardens such the implant 60 becomes rigid. By way of non-limitingexample, one suitable hardening material includespolymethylmethacrylate.

In use, as shown in FIGS. 6A-6B, the spinal implant 60 can be insertedbetween two adjacent vertebrae located at a substantial apex A of acurvature of a spinal deformity. FIGS. 6A-6B illustrate a curvature in acoronal plane of adjacent vertebrae of a spine, showing a convex side Bof the curvature and a concave side C of the curvature. Varioustechniques can be used for introducing the implant 60 into the discspace between two adjacent vertebrae, but in an exemplary embodiment asshown in FIG. 6A, the implant 60 is preferably inserted into the discspace by accessing the convex side B of the abnormal spinal curvature.Prior to insertion of the implant 60, the intervertebral disc orportions thereof can be removed from the disc space. Followingpreparation of the disc space, the implant 60 can be oriented betweenthe adjacent vertebrae in its deflated configuration and is positionedsuch that the first lateral side 62A, i.e., the side having the maximumheight upon inflation, is located on the lateral side of the disc spaceadjacent to the concave side C of the curvature. The opposed secondlateral side 62 b, i.e., the side having the minimum height uponinflation, is located on the opposed lateral side of the disc spaceadjacent to the convex side B of the curvature. As shown in FIG. 6B,once the implant 60 has been introduced and properly positioned, theimplant 60 can be inflated with the syringe 100 such that the implant 60attains the wedged-shape configuration. As a result, the implant 60interrupts the curvature in the coronal plane, thereby correcting thedeformity.

FIGS. 7A-7C illustrate another exemplary embodiment of a spinal implantthat is capable of being adjusted. As shown in FIG. 7A, in thisembodiment the implant 70 can include a base 71 with a pivotingcomponent 73 mounted thereon. The pivoting component 73 can be attachedto the base 71 using, for example, a pin joint 75. In use, the pin joint75 allows the pivoting component 73 to oscillate on the base 71 betweena neutral configuration (FIG. 7A), an initial configuration (FIG. 7B),and a final configuration (FIG. 7C). The implant 70 also includes firstand second opposed lateral sides 72 a, 72 b. Each of the lateral sides72 a, 72 b can have a height that is greater than the height of theopposed lateral side depending on the position of the pivoting component73. For example, as shown in FIG. 7B, when the pivoting component 73 isadjusted to an initial configuration, the first lateral side 72 a has aheight h_(iii) that is less than a height h_(iv) of the opposed secondlateral side 72 b. As illustrated in FIG. 7C, when the pivotingcomponent 73 is configured in a final position, the first lateral side72 a can have a height h_(v) that is greater than a height h_(vi) of theopposed second lateral side 72 b.

To retain the pivoting component 73 in a particular configuration, theimplant 70 can further include a locking mechanism. While variouslocking mechanisms can be used, in one embodiment the locking mechanismcan include a set of ridges 77 formed on a surface of the pivotingcomponent 73 and a set of corresponding grooves 79 formed on a surfaceof the base 71. The ridges 77 mate with grooves 79 such that thepivoting component 73 is locked into a position on base 71. In use, inorder to adjust the position of the pivoting component 73, a ratchetingmechanism 200 (FIG. 7E) can be used to engage and manipulate thepivoting component 73 by, for example, tensioning the pivoting component73 from the initial configuration to the final configuration.

FIGS. 7D-7E illustrate an exemplary method for correcting a curvaturedeformity in a coronal plane of a spinal column using the implant 70 ofFIGS. 7A-7C. In this embodiment, the implant 70 can be introduced intothe intervertebral disc space between two adjacent vertebrae, with thepivoting component 73 of the implant 70 located in the initial position(FIG. 7D), such that the minimum height, i.e., the first lateral side 72a, is introduced first into the disc space with the second lateral side72 b trailing. The implant 70 can then be adjusted to a final position(FIG. 7E), thereby correcting the abnormal spinal curvature. Althoughvarious techniques can be used for introducing the implant 70 into thedisc space, in an exemplary embodiment the implant 70 can be introducedby accessing the spinal column in a lateral direction on a convex sideof a curvature. As shown in FIG. 7D, the implant 70 can be inserted intoa disc space in the initial configuration such that the first lateralside 72 a has a lower height than the opposed second lateral side 72 b.The implant 70 is oriented in the disc space such that the first lateralside 72 a is adjacent to the concave side C of the curvature, and thesecond lateral side 72 b is adjacent to the convex side B of thecurvature. As illustrated in FIG. 7E, following the insertion of theimplant 70 within the intervertebral disc space, the ratchetingmechanism 200 can be used to adjust the pivoting component 73 of theimplant 70 from the initial configuration to the final configurationsuch that the first lateral side 72 a has a height that is greater thana height of the opposed second lateral side 72 b. As a result, theheight along the concave side C of the curvature is increased, thusinterrupting the abnormal curvature and thereby correcting the spinaldeformity.

A person skilled in the art will appreciate that the various implantsdisclosed herein can be oriented in various directions, other than thoseillustrated, to achieve the desired results. In particular as previouslyexplained, the use of the terms posterior and anterior are merelyprovided for convenience and do not limit the implant to being orientedsuch that the posterior side is located adjacent to the posterior sideof the disc space and the anterior side is located adjacent to theanterior side of the disc space. The implant can be oriented in variouspositions within the disc space and relative to the curvature to achievecorrection. In an exemplary embodiment, however, the side of the implanthaving the maximum height (i.e., a height greater than the opposed side)is positioned adjacent to the side of the disc space located on theconcave side of the curvature.

The various implants disclosed herein can be formed from a variety ofmaterials, and they can include various other features. For example, theimplants can be made from any suitable biocompatible material such asbone, metal, metal alloys, plastics, and/or carbon fiber. In anotherexample, the implants can have a solid structure with openings or bores,or a skeletal frame. The openings and skeletal frame permit varioussubstances to be introduced into the implants, such as, for example,osteobiologics and bone growth promoting factors. Alternatively, theimplants can be coated with such substances to promote fusion of theimplants with the vertebrae between which the implants are interposed.In yet another example, the implants can include a variety of surfacefeatures for engaging the endplates of the vertebrae. Such surfacefeatures can include for example, spikes, serrations, and/or ridges.

The implants can also be provided as a kit. The kit can include aplurality of intervertebral wedged implants. Each implant can include abody have an upper surface and an opposed lower surface, opposed firstand second ends that extend between the upper and lower surfaces, andfirst and second sides extending between the upper and lower surfacesand the first and second ends. In one embodiment, the upper and lowersurfaces of the implants can be oriented at an angle relative to oneanother, and in an exemplary embodiment the angle of each implant canvary by increments of about 5° to 30°. In another embodiment, the firstend of each implant can have a height that is greater than a height ofthe opposed second end, and/or the first side of each implant can have aheight that is greater than a height of the opposed second side. Thedifference in height between the first and second ends and/or the firstand second sides can define an angle, and in an exemplary embodiment theangle of each implant can vary by about 5° to 30°.

In an exemplary embodiment, the various implants discussed herein can beused in combination with a spinal fixation construct. For example, oneor more implants can be positioned at one or more levels of the spine,as previously described. Once the curvature is corrected, a spinalfixation system can be implanted in the spine to maintain the vertebraein the correct orientation. FIG. 8 illustrates a spinal implant 80positioned between two adjacent vertebrae, and a spinal fixation systemfixedly mated to a posterior side of the spinal column and extendinglongitudinally along lateral sides of adjacent vertebrae. The spinalfixation system generally includes first and second bone anchors 90 a,90 b implanted in opposed lateral sides or each vertebra, and first andsecond spinal rods 92 a, 92 b seated within the bone anchors andextending longitudinally along opposed lateral sides of the spine. Thespinal fixation system provides enhanced stability and reinforces thecorrection of the abnormal spinal curvature provided by the spinalimplants of the present invention. A person skilled in the art willappreciate that the system can include only one fixation rod extendingalong one lateral side of the spine, and that various other fixationsystems and techniques known in the art can be used.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

1. A method for correcting a spinal deformity, comprising: inserting aspinal implant into a disc space formed between two adjacent vertebraelocated along a curvature resulting from a deformity in a spinal column,the disc space including a first lateral side located adjacent to aconcave side of the curvature in the spinal column and a second lateralside located adjacent to a convex side of the curvature in the spinalcolumn, and the spinal implant having a wedge-shaped configuration witha first side having a height that is greater than a height of a secondopposite side; and positioning the first side of the spinal implantadjacent the first lateral side of the disc space such that a height ofthe first lateral side of the disc space is greater than a height of thesecond lateral side of the disc space to correct the spinal deformity.2. The method of claim 1, wherein the second opposite side of the spinalimplant is positioned adjacent the second lateral side of the discspace.
 3. The method of claim 2, wherein the spinal implant has afootprint that substantially matches a footprint of endplates of theadjacent vertebrae.
 4. The method of claim 1, further comprisinginserting a second spinal implant into the disc space, the second spinalimplant having a wedged-shaped configuration with a first side having aheight greater than a height of a second opposite, the height of thefirst side of the second spinal implant being less than the height ofthe first side of the first spinal implant, and positioning the secondside of the second spinal implant adjacent the second lateral side ofthe disc space.
 5. The method of claim 1, wherein the spinal implant hasopposed posterior and anterior sides extending between the first andsecond sides, the posterior side having a height greater than a heightof the anterior side such that a height of a posterior side of the discspace is greater than a height of an anterior side of the disc space. 6.The method of claim 1, wherein the spinal implant has opposed posteriorand anterior sides extending between the first and second sides, theanterior side having a height greater than a height of the posteriorside such that a height of an anterior side of the disc space is greaterthan a height of a posterior side of the disc space.
 7. The method ofclaim 1, wherein the spinal implant is inserted through an incisionformed in an anterior side of a patient's body, and is positioned suchthat the implant fills a substantial portion of the disc space.
 8. Themethod of claim 1, wherein the spinal implant is inserted through anincision formed in a posterior side of a patient's body, and is guidedinto a position adjacent the concave side of the curvature of the spinalcolumn.
 9. The method of claim 8, further comprising a second spinalimplant inserted through the incision formed in the posterior side ofthe patient's body, and is guided into a position adjacent the convexside of the curvature of the spinal column.
 10. The method of claim 1,further comprising removing at least a portion of an intervertebral disclocated between the adjacent vertebrae prior to inserting the spinalimplant.
 11. The method of claim 1, further comprising mating at leastone connecting element extending longitudinally along the spinal columnto the adjacent vertebrae.
 12. The method of claim 1, wherein insertingthe implant comprises positioning the implant in a deflatedconfiguration into the disc space, and inflating the implant into aninflated configuration such that the implant has a wedge-shapedconfiguration with a first side having a height that is greater than aheight of a second opposite side.
 13. The method of claim 12, whereinthe implant is inflated with a material that hardens such that theinflated implant is rigid.
 14. The method of claim 1, wherein insertingthe implant comprises positioning the implant in a first orientation inwhich the first side has a height that is less than a height of thesecond opposite side, and adjusting the implant into a final orientationin which the first side has a height that is greater than a height ofthe second opposite side.
 15. A method for correcting a spinaldeformity, comprising: inserting a wedged implant between two adjacentvertebrae located at an apex of a curvature resulting from a deformityin a spinal column; and orienting the wedged implant such that a heightbetween the adjacent vertebrae is increased along a concave side of thecurvature to interrupt the curvature of the spinal deformity and therebycorrect the spinal deformity.
 16. The method of claim 15, wherein thewedged implant is inserted between the adjacent vertebrae using aposterior approach.
 17. The method of claim 15, wherein the wedgedimplant is inserted between the adjacent vertebrae using an anteriorapproach.
 18. The method of claim 15, further comprising removing atleast a portion of an intervertebral disc between the adjacent vertebraeprior to inserting the wedged implant.
 19. The method of claim 15,further comprising mating at least one connecting element extendinglongitudinally along the spinal column to the adjacent vertebrae. 20.The method of claim 15, wherein inserting the wedged implant comprisespositioning the wedged implant in a deflated configuration between twoadjacent vertebrae, and inflating the wedged implant into an inflatedconfiguration such that the a height between the adjacent vertebrae isincreased along a concave side of the curvature.
 21. The method of claim20, wherein the implant is inserted on a convex side of the curvature.22. The method of claim 15, wherein inserting the wedged implantcomprises positioning the wedged implant in a first orientation in whicha first side has a height that is less than a height of a secondopposite side, and adjusting the wedged implant into a final orientationin which the first side has a height that is greater than a height ofthe second opposite side to increase a height between the adjacentvertebrae along the concave side of the curvature.